The present invention is directed to the art of packaging materials, and more particularly to the art of plastic bundling and palletizing materials.
The present invention is especially concerned with the art of plastic stretch wrap film, and will be described with particular reference thereto.
Stretch wrap films of the prior art are used in connection with a variety of overwrap packaging applications. They are typically applied to pallet loads, boxes, sheeted materials and other items in an effort to secure them for shipping or transport. The existing stretch wrap films provide desirable results when used in connection with products that are not required to breathe.
A problem with conventional stretch wrap materials is that they tend to restrict air flow to and from the wrapped or packaged items. Existing stretch wraps often cause irreparable damage, such as warping or the formation of rot, mold or mildew, to merchandise that requires the ability to breathe. For example, existing stretch wraps are undesirable in situations where the products to which they are applied are packaged at elevated temperatures. Food items, such as dog food, are known to be packaged while they are still hot. It is necessary for the heat to dissipate, and the existing wraps do not provide for this. Similarly, many types of bottles are labeled (i.e. wine bottles) and packaged while the label is still hot. By retaining the heat, the label is often damaged.
Beverages, too, often form condensation on the surfaces of their cans and bottles. The condensation must be allowed to escape and existing stretch film wraps do not permit this.
In addition, preexisting film wraps tend to suffocate items such as fresh produce, food, products packed hot, fabric and tobacco. The existing stretch wraps do not permit gases, vapors, or heat to escape from a wrapped pallet load. Moreover, existing stretch wraps often permit molding and hence, damage to fabrics, furniture and crops.
Attempts have been made to overcome the problems described above. For example, existing wrapping machinery has been modified to include a perforator on the stretcher mechanism. Perforations made by this mechanism cause tearing in the stretch wrap and the wrapping is not secure.
Other attempts have been made as well. For example, netting has been used as an alternative to stretch wrap because of its ability to breathe. Netting is most commonly seen in connection with fruits, such as apples and oranges. Netting is, however, undesirable because it is expensive and has poor load retention. Also, there is a danger that workers or machinery may become caught in the netting, causing serious injury or damage.
It would be desirable to develop a stretch film that is breathable as well as strong. It would be further desirable to develop a method for making such a breathable, strong stretch film.
The present invention contemplates a new and improved air permeable stretch wrap which overcomes all of the above problems and others and provides a bundling or palletizing material which is strong, flexible and fluid permeable.